By: Jeremy Anderson Posted at: 04/15/2013 02:11 PM SIOUX FALLS, S.D. (AP) - A landowner trying to sell a fraction of the Wounded Knee National Historic landmark in South Dakota says he has had three offers from West Coast-based investment groups.

James Czywczynski says he is giving the Oglala Sioux Tribe until May 1 to make an offer on the land before he opens it up to outside buyers.

Czywczynski would not give details on the groups but says they are willing to pay the full $3.9 million asking price.

Czywczynski's family has owned the 40-acre parcel of land since 1968. The land sits adjacent to where 300 Lakota men, women and children were killed by the 7th Cavalry in 1890.